Dipole modelling of metal magnetic memory for V-notched plates

作者：Leng J C^*; Xing H Y; Zhou G Q; Gao Y T

来源：Insight, 2013, 55(9): 498-503.

DOI：10.1784/insi.2012.55.9.498

• Metal magnetic memory
• magnetic dipole
• stress concentration
• magnetic charge

The metal magnetic memory (MMM) technique is hardly capable of evaluating early damage quantitatively owing to the lack of a rigorous and self-consistent theoretical model. Taking into account that previous magnetic models focus mainly on magnetic signal variation with stress, in this paper a linear magnetic dipole model has been developed to represent the self-magnetic leakage field distribution due to stress concentration in a V-notched plate. The magnetic charge density distribution is assumed to be identical to the dislocation density distribution in the plastic zone at a crack tip. Simulation and analysis show that both the normal and tangential components of MMM signals can capture basic characteristics regarding the early damage obtained in experiments, and it is also shown that the MMM signals in the stress concentration zone decrease obviously with increasing lift-off values, indicating that the proposed model can provide a quantitative prediction of the degree of damage and range, respectively.

• 出版日期2013-9
• 单位东北石油大学